Many doors, either commercial or residential, are purchased as pre-hung door assemblies. A pre-hung door assembly is delivered for installation with the door already hingedly connected to the door frame that is to be inserted into the building opening where the door is to be located. Pre-hanging is accomplished by attaching the door to one side of the door frame, typically by one or more hinges. The other side of the door may be provided with a lockset and knob opening. The jamb member positioned immediately adjacent to the lockset and knob opening side is fitted with a latch or striker plate and associated opening so that the door can be securely shut after it has been installed. Pre-hanging is usually performed at the door-making facility, which typically is remote from where the door and its frame are to be installed. Once the door has been pre-hung it needs to be shipped, typically by truck, to the building location.
Doors, especially pre-hung door assemblies, are usually stored by placing one directly adjacent to another front-to-back. This method of storage maximizes space usage by eliminating spaces between adjacent door assemblies. It is, therefore, desirable to have a door frame with a small foot print so that wasted space is further eliminated for efficient storage and enhanced logistic efficiencies. In other words, more doors and their frames can be shipped by truck if the foot print is reduced. Shipping can be expensive and thus costly, so minimizing that expense is important to reducing costs.